Ultrasound Probes Aid Minimally Invasive Surgery

If the probes prove beneficial in human testing, this development might lead to more accurate and safer endoscopic surgeries, according to the Duke engineers. "Surgeons now use optical endoscopes or two-dimensional ultrasound when conducting minimally invasive surgery,” said lead engineer Dr. Stephen Smith, a professor of biomedical engineering at the Pratt School. Optical endoscopes are thin tubes with a tiny video camera that surgeons can insert directly into the abdomen or chest through small incisions. "With our scanner, doctors could see the target lesion or a portion of an organ in a real-time three-dimensional scan,” Dr. Smith said.

The technology has not yet been evaluated in human patients, but its success in canines makes it ready for clinical trials, according to the researchers. Endoscopic surgical techniques have the advantage of reduced postoperative pain and a faster recovery. However, the two-dimensional (2D) ultrasound imaging now available provides surgeons only a limited view, which can impede their depth perception and make such procedures difficult to master.

The current development relies on 500 miniature cables and sensors stuffed into a tube 12 mm in diameter--the size required to fit into surgical instruments, called trocars, that surgeons use to allow easy exchange of laparoscopic tools. By comparison, most 2D ultrasound probes use just 64 cables. Each cable carries electrical signals from the scanner to the sensors at the tip of the tube, which then sends pulses of acoustic waves into the surrounding tissue.

The 3D ultrasound probes also might help guide clinicians during cardiac ablation therapy, he added. In such procedures, cardiologists use catheters to ablate, or burn, specific locations on the surface of the heart in patients with atrial fibrillation, a disorder typified by an abnormal heart rhythm.
Similar 3D ultrasound devices also hold promise for minimally invasive abdominal and brain surgery applications, according to Dr. Smith.